[ male announcer ] campbell's chunky soup. it fills you up right. >> pelley: president obama is keeping up the pressure on congress to pass new gun control legislation. he met at the white house today with police officials from around the country, including aurora, colorado, oak creek, wisconsin, and newtown, connecticut-- the scenes of recent mass shootings. the president called on congress to pass an assault weapons ban. in chicago, gun violence is taking more lives-- 50 since newtown. and dean reynolds tells us it has been another deadly weekend. >> reporter: among the seven people murdered in chicago this past weekend was 33-year-old ronnie chambers, shot dead in a parked van. he was the last surviving child of shirley chambers who now has lost all four of her children to gun violence. we spoke to her today at a local funeral home. do you think that there's something sick in chicago? >> it's not chicago, it's these people with these guns, this -- they shouldn't have the guns, you know? >> reporter: her son was a former gan